RockySierra wrote:Your truck will not last any longer just by simply running amsoil or some other "premium" name oil in it. Spend your money wisely. Transmissions with the exception of the Allison are not built to last 200,000 miles unless you are doing a ton of highway driving.

The 4L60E in my 97 Sierra had roughly 300,000 miles on it, and had no issues whatsoever when I traded it in for my current truck. I know for a fact that the 4L80E will last longer in my current truck now that it's full of nothing but AMSOIL, than if I hadn't changed over to AMSOIL. Why? Because it has reduced the operating temps, and smoothed out the operation of the transmission. Since I do a lot of plowing\towing\hauling, the less heat and roughness I see from the transmission, the longer it will last.

Never claimed you should change your oil every 3000 miles. GM has not either, ever since they introduced the oil life monitor, going back to 1999 and even further. Sorry, but I've been around way too many forums and had much too personal experience to buy the sales game you folks with Amsoil try to use. No offense but in my opinion, anyone who buys your products thinking that they will get longer life out of their vehicles are fools.

RockySierra wrote:Your truck will not last any longer just by simply running amsoil or some other "premium" name oil in it. Spend your money wisely. Transmissions with the exception of the Allison are not built to last 200,000 miles unless you are doing a ton of highway driving.

How many miles is an Allison tranny built to last I just killed my 3rd one last week in my work truck it only has 122,000 on the truck.

scooter2008 wrote:Hey guys, I have a 08 LS crew cab 1500 4wd with 40,000 miles. I wanted to get your opinion on switching over the tranny and diff to synthetic I've heard some of the benefits but would like to hear your thoughts. Also has anyone seen any gains in mpg with running synthetic? Thanks

It looks like this thread sorta drifted from your original question.

My other vehicle is a 2000 4WD Cherokee. And I went mostly synth with it; front and rear diffs, transfer case and motor oil. I saw no reason for changing the tranny to full-synth as there is not any drag created by the tranny because its working anytime you're running as opposed to say the front diff and t-case which don't. Not to mention cost ....buying three gallons of Castrol synthetic tranny fluid was just a little too dear for my wallet ...especially after buying the gear lube at $20 a bottle and the Mobil 1 ATF for the t-case. Synthetics generally flow better when cold so I thought there would be some savings to had as opposed to the dino oils which tend to be thicker and offer greater resistance or drag until they warm up. If there was an increase in MPG's it was so small as to be negligible ...I did not see any change in my fuel mileage and, yes, I figure it by doing the math.

My thoughts on tranny fluid. The biggest enemy to tranny fluid is heat. The stuff will generally last a long time unless it gets overheated and then it breaks down pretty quickly. You need to consider compatibility with your tranny; GM requires a Dexron VI - certified fluid. You need to consider how you will be using your truck ...are you going to be towing with it on a regular basis ...do you live in some extreme climate (like AZ or AK)? I tow a 6500 lb trailer a few times a month and my truck has the optional tranny cooler as part of its towing package. When I bought my truck last summer one of the first things I did was a fluid flush ...at the dealer using Dex VI. Because of the occasional heavy towing I will probably swap it again next year. Why? Because its cheap insurance. Now if I had my tranny filled with some high exotic synthetic fluid I would still feel the need to make regular changes on it ...regardless of what the fluid manufacturer promises or claims ....its just that the fluid change would be a lot more expensive to do. I don't live in an extreme climate and for me, standard issue Dexron VI makes sense.

Overall, true synthetics are more stable and are "engineered" from scratch for their intended purposes so they probably have a higher durability factor. Whether you need this higher durability and your willingness to pay for it are up to you to decide. As for any MPG increases, I think you can forget that.

Mike

I'm not so much a smart guy as a guy smart enough to know how to find out....'98 Sierra SL 305 Reg Cab Short Bed

RockySierra wrote:Never claimed you should change your oil every 3000 miles. GM has not either, ever since they introduced the oil life monitor, going back to 1999 and even further. Sorry, but I've been around way too many forums and had much too personal experience to buy the sales game you folks with Amsoil try to use. No offense but in my opinion, anyone who buys your products thinking that they will get longer life out of their vehicles are fools.

I have no connections with AMSOIL, other than the fact that I buy their products. The oil industry is very, very competitive, and there are two things that won me over: The quality and integrity of the company\salespeople, and the independent tests that they publish, demonstrating their product's superiority over all others.

No, that is not true. It does not require certified fluid, only that the fluid meet the spec's for Dexron VI.

Here is what the owners manual says for my GM vehiclesDEXRON®-VI Automatic Transmission Fluid. It does not says certified.

Umm ...I don't want to get into a urinating contest here but the "DEXRON-VI" moniker on a label of aftermarket tranny fluid means it meets GM's specifications, ie; it has been certified to meet the GM DEXRON-VI specifications for transmission fluid. Aftermarket vendors have to pay for this certification in order to market their fluid as DEXRON-VI.

I might be wrong on this but it's my understanding AMZOIL didn't fork over the moolah ...so they cannot claim a DEXRON-VI compatibility with their transmission fluid.

mike

Mike

I'm not so much a smart guy as a guy smart enough to know how to find out....'98 Sierra SL 305 Reg Cab Short Bed

No, that is not true. It does not require certified fluid, only that the fluid meet the spec's for Dexron VI.

Here is what the owners manual says for my GM vehiclesDEXRON®-VI Automatic Transmission Fluid. It does not says certified.[/quote]

Umm ...I don't want to get into a urinating contest here but the "DEXRON-VI" moniker on a label of aftermarket tranny fluid means it meets GM's specifications, ie; it has been certified to meet the GM DEXRON-VI specifications for transmission fluid. Aftermarket vendors have to pay for this certification in order to market their fluid as DEXRON-VI.

I might be wrong on this but it's my understanding AMZOIL didn't fork over the moolah ...so they cannot claim a DEXRON-VI compatibility with their transmission fluid.

mike[/quote]

i agree 100% with what your saying obv the site is going to be a little biased with sponsors........... i wonder how all of our trucks survived before without synthetics, or the fact its not even consierded as a better recommendation from the manufacter, in the boat world where i work they call the oils synthetic blend and by syntheic blend it means a tea spoon of additives to a gallon of oil........... and even they dotn recomment full synthetic on there engines except for a few newer emission control engines however there intervals stay the same as the others.....granted we know a marine engine works harder than a truck (operating a fixed ratio at usually 3800-5500rpm

basically i dont justify replacing engine oil with full syn i can see differental and longer sched maint items but not engine oil idc what you say but if working my eninge oil i aint gonna trust it for 25000 miles will it do it yes any oil will do that but is it right .....idk

*Sigh*......Can't we all just get along?The fact that this debate is even occurring shows that most of us are passionate about good maintenance. Because of that, we will all see pretty good longevity from our vehicles. It may or may not be a measurable difference, because other factors such as driving habits, location, etc play into the equation. It may or may not show up in our MPG's, either.

Why I use Amsoil -- For my part, I like having a reputable product, supported by lots of testing, and also supported by a reputable dealer who sponsors my favorite website. Oh yes...and the stuff magically appears on my doorstep 2 days after I order it. So, I like Amsoil.

And now I am talking syn vs. dyno, not just Amsoil -- I like knowing that on the days I don't baby my truck, I might just have that little extra margin of quality that helps it survive a good thrashing, or an extended period of use without maintenance. I like that the pour points of synthetics are lower. I like that most of the testing shows reduced wear (4 ball wear testing). I like that the volatility is lower. I like that the worlds premium vehicles, built to the tightest tolerances recommend syn as the factory fill. In general, I like knowing that after paying darn near $45k for a vehicle, I am giving it the BEST I can to get the max life from it. Call me a fool....

Transmission and drivetrain related components. Discuss automatic and manual trans repairs and performance or talk about driveshafts or rear-ends and differentials. Diagnostics of 4-speed, 5-speed, or even 6-speed transmissions.